Testosterone therapy gets a Pentagon push as doctors urge caution

The U.S. military is preparing to check service members’ testosterone levels and offer replacement treatment to those who meet the criteria, Defense Secretary Pete Hegseth said last week.

Hegseth said the aim is to help troops perform at their best. The plan lands as the Trump administration has promoted wider access to testosterone replacement therapies, a market that includes drugmakers such as AbbVie, Pfizer and Marius Pharmaceuticals.

The treatment has also surged far beyond traditional specialist care. Men’s health clinics, telehealth firms and online influencers have helped turn testosterone into a buzzy wellness product tied to fatigue, aging and performance. Health and Human Services Secretary Robert F. Kennedy Jr. has said he uses testosterone therapy as part of an anti-aging routine.

Prescriptions climbed from 7.3 million in 2019 to more than 11 million in 2024, according to health-care research firm IQVIA.

Who is supposed to get it

Testosterone replacement therapy uses synthetic testosterone and can be given through injections, gels, pellets placed under the skin or oral medication. Doctors say it is generally meant for men with confirmed hypogonadism, a condition in which the body does not make enough testosterone.

That diagnosis usually involves repeated low testosterone readings along with symptoms such as reduced sex drive, erectile dysfunction, fatigue, depressed mood, low bone density, or loss of muscle mass and strength.

Dr. Adrian Sandra Dobs, an endocrinologist at the Johns Hopkins School of Medicine, said the treatment can help people who need it, while warning that giving too much hormone requires caution.

Marcus Goncalves, director of the Holman Division of Endocrinology, Diabetes and Metabolism at NYU Langone Health, said obesity, stress, poor sleep and fatigue can reduce testosterone. In those cases, he said doctors often look first at fixing the underlying problem.

Medical guidelines generally call for two separate morning blood tests because testosterone levels change over the course of a day, Goncalves said. Doctors also look for causes such as sleep apnea, testicular injury, pituitary disorders, cancer treatments or chronic illness.

The American Urological Association says as many as one-third of men taking testosterone have not been formally diagnosed with testosterone deficiency.

Benefits, risks and the military wrinkle

For men with a confirmed deficiency, doctors say testosterone therapy can improve sex drive, erectile dysfunction, muscle mass, bone density, energy and mood. It may also lower osteoporosis and fracture risk in men with low hormone levels.

Experts told CNBC the case is weaker for using testosterone in men whose levels are normal or only slightly low, especially for broad claims about anti-aging, cognition, athletic ability or general performance.

The risks require monitoring. Goncalves said testosterone can raise red blood cell counts, which may thicken blood and increase the chance of complications such as clots. It can also reduce sperm production and affect fertility, so doctors generally discourage it for men who may want children.

Other possible side effects include acne, breast tenderness or enlargement, fluid retention and worsening untreated sleep apnea.

A large 2023 trial found no higher rate of heart attack, stroke or cardiovascular death among men using testosterone therapy compared with men given a placebo. Researchers did see higher rates of atrial fibrillation, acute kidney injury and pulmonary embolism.

Military testing adds a special complication. Goncalves said intense training, sleep loss and prolonged exertion can temporarily push testosterone down. One study of U.S. Marines in Survival, Evasion, Resistance and Escape training found testosterone levels fell by about half during the exercise and later recovered.

Dr. Richard Auchus, a professor of internal medicine at the University of Michigan, said a low reading in that setting may reflect a temporary stress response rather than a lasting medical condition. He also warned that long-term treatment can suppress natural testosterone production, creating problems if a service member loses access to the medication during deployment or another operation.

This story draws on original reporting from CNBC.